Gilbert 1985.

Study characteristics
Methods	Study design: RCT Recruitment period: not reported, duration 10 months Recruitment mode: all people who presented with LBP to 22 participating family physicians. Physicians were drawn from both single‐handed and group practices, worked predominantly in urban areas, and cared for an average of 2000 patients. Statistical analysis: ANOVA controlling for baseline measures to assess patient diary outcomes and survival analysis (Cox proportional hazards model) Sample size calculation: based upon determining a clinically important difference of 1 SD on the activity discomfort scale
Participants	Sample size: total: 252; EG1: 65, EG2: 62, CG1: 60, CG2: 65 Setting: primary care, family practice Country: Canada Baseline characteristics Age in years, mean (SD): EG1: 40.7 (14); EG2: 41.7 (15.3); CG1: 40.0 (14.9); CG2: 40.1 (14.5) Sex, number (%) women: EG1: 33 women (51%); EG2: 33 women (53%); CG1: 30 women (50%); CG2: 28 women (43%) Duration LBP: (<6 days versus ≥ 6 days): EG1: 41 versus 24; EG2: 30 versus 32; CG1: 29 versus 31; CG2: 35 versus 30 Inclusion criteria Over 16 years of age Complaining of lumbosacral pain (with or without radiating pain in the lower extremity) Free of pain for at least 30 days prior to the current episode Exclusion criteria Subjects had abnormal sensation, motor power, or reflexes If the subjects' symptoms were proven to be due to fractures Pregnancy Spondylolisthesis Spinal infection Disease of the hip or pelvis Gastrointestinal disease Tumour Paget's disease Rheumatic disease
Interventions	EG1: exercise and education plus bed rest Description: isometric flexion exercise, advice to repeat exercises at home 3 times a day Materials/equipment: not reported Non‐exercise component: 4 days bed rest, education (20 minutes presentation on back care + information sheet), analgesic Frequency and duration: repeat visits as necessary, otherwise not reported Delivery: partially independent, individual supervised generic sessions and unsupervised home programme component Provider: PT EG2: exercise and education alone Description: isometric flexion exercise, advice to repeat exercises at home 3 times per day Materials/equipment: not reported Non‐exercise component: education (20 minutes presentation on back care + information sheet), analgesic Frequency and duration: repeat visits as necessary Delivery: partially independent, individual supervised generic sessions and unsupervised home programme component Provider: PT CG1: bed rest 4 days' bed rest, analgesics CG2 Analgesics, no other treatment
Outcomes	Note: outcomes were not defined as major or minor Pain: MPQ (0–78) Baseline, mean (SD): EG1: 23.0 (7.4); CG1: 25.2 (8.6); EG2: 22.7 (6.7); CG2: 25.1 (6.9) 6 weeks, mean (SD): EG1: 22.7 (6.7); CG1 25.2 (8.6); EG2: 23 (7.4); CG2: 25.1 (6.9) Follow‐up, mean (SD): EG1: 7.5 (1.2); CG1: 7.9 (2.0); EG2: 8.4 (0.9); CG2: 8.6 (1.3) In the meta‐analyses, all values are multiplied by 1.28 to convert to a 0–100 scale Functional status: ADS (0–78) Baseline measure: no 6 weeks, mean (SD): EG1: 35.9 (13.7); CG1: 36.3 (13.1); EG2: 40.4 (16.4); CG2: 36.6 (12.4) Follow‐up, mean (SD): EG1: 24.4 (8.8); CG1: 24.3 (9.2); EG2: 21.3 (10.0); CG2: 20.9 (8.5) In the meta‐analyses, all values are multiplied by 1.28 to convert to a 0–100 scale Perceived recovery: pain no worse than mild according to participant and physician 6 weeks, number recovered/total: EG1: 48/61; CG1: 44/56; EG2: 48/60; CG2: 42/58 12 weeks, number recovered/total: EG1: 53/63; CG1: 49/57; EG2: 54/62; CG2: 53/60 Other: medication use for their LBP and any other measures that they used to alleviate the pain, bed rest was monitored with an integrated motor activity monitor At 1 year of follow‐up: frequency and severity of any episode of LBP, current activity level, and if they had seen a professional for their LBP Adverse events: not reported
Notes	Authors' results and conclusions: no beneficial effect of either treatment was observed on clinical outcome measures Funding: funded by Ontario Ministry of Health (DM 500; Governmental) Declaration of interest: no conflicts of interest reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "After obtaining informed consent the physicians telephoned a centralised patient registry and randomisation service in the department of epidemiology and biostatistics, Mc. Master University. Patients were stratified within each practice by whether their physician intended to place them on minor or major medications. Within each strata, patients were randomly assigned to one of four treatment groups." No further text on how the sequence was generated.
Allocation concealment (selection bias)	Unclear risk	Unclear who was responsible for allocation and if this person could foresee the assignment.
Blinding All outcomes ‐ Participants	High risk	No mention of any attempts to blind participants to other interventions, treatment allocation, or their perceptions of the potential effectiveness of the different interventions.
Blinding All outcomes ‐ Healthcare providers	High risk	No mention of any attempts to blind the study physiotherapist. The physician was blind to the participant's assigned treatment.
Blinding All outcomes ‐ outcome assessors	High risk	The outcome measures were self‐reported and participants were unblinded.
Influence of co‐interventions	Low risk	Co‐interventions were similar among treatment groups.
Group similarity at baseline	Low risk	The 4 treatment groups were well balanced on 13 key variables. Some significant and clinically important differences were observed. Participants randomised to the educational programme were better at baseline on 3 measures. These baseline differences were taken into account in the analyses.
Compliance	Low risk	Compliance with bed rest, exercise, and back care techniques were measured by means of a diary in which all participants recorded the time they spent resting and exercising every day, their daily activities, and any restrictions. 89% of participants completed at least one 10‐day patient diary. Participants in the exercise group also reported to the research assistant at the 6‐ and 12‐week telephone interviews the extent to which they continued to follow the exercise and back care program. Activity monitors (worn on the wrist to record body movement) were used by randomly selected participants to obtain an objective measure of daily activity. However, the monitors proved to be unreliable and thus no objective measure of compliance with bed rest could be obtained. Compliance with physiotherapy was determined in part by participants returning for their physiotherapy education. All but 2 of the participants randomised to physiotherapy and education saw the physiotherapist at least once, and no participants in the non‐physiotherapist groups received the physiotherapy and education programme.
Timing of outcome assessments	Low risk	During the intervention each time participants visited the GP (with a 10‐day interval until the pain had subsided); and at 6 and 12 weeks, and 12 months after the participant's entry into the project. All important outcomes were measured at the same time across groups.
Incomplete outcome data (attrition bias) Dropouts – all outcomes	Low risk	Some participants dropped out. 87% returned to their physician for follow‐up evaluation. A telephone follow‐up was completed for 96% of participants at 6 and 12 weeks and for 90% at 1 year.
Intention‐to‐treat‐analysis	High risk	10 participants were excluded from the analysis because they did not undergo the assigned therapy. 8 participants were excluded because they did not fulfil the eligibility criteria.
Selective reporting (reporting bias)	Low risk	A study protocol is not available, but all prespecified outcomes and important outcome measures in LBP research were reported: pain (MPQ), function (ADS), perceived recovery.
Other bias	Unclear risk	Governmental funding. No official disclosure regarding potential conflicts of interest.